scholarly journals Influence of different chemical agents and storage conditions on the microbiological content of industrial hemp (Cannabis sativa L.) seeds

2020 ◽  
Vol 47 (2) ◽  
pp. 159-168
Author(s):  
Nataša Đerić ◽  
Olja Todorić ◽  
Milana Rošul ◽  
Sunčica Kocić-Tanackov ◽  
Vladimir Sikora ◽  
...  

This study aimed to test different chemical agents to obtain microbiologically safe industrial hemp seeds that could be used for further food processing (with the reduced total number of microorganisms, total number of moulds and yeasts, and total number of Enterobacteriaceae). In order to obtain seeds applicable for food consumption, optimal storage temperature conditions (room temperature, refrigerator, freezer), method of seed packaging (vacuum/without vacuum), and the application of various chemical treatments (ethanol, sodium hydrogen carbonate, sodium hypochlorite) were tested on the certified industrial hemp seeds, produced in two consecutive years. Optimal storage conditions differed for different microorganisms, and the most optimal storage was at room temperature, for seeds produced in 2018, in the treatment to reduce the total number of Enterobacteriaceae and the total number of microorganisms. When storing seeds from 2018 in order to reduce the number of yeasts and moulds, a slightly lower number was spotted when seeds were stored in a vacuum-sealed bag, at the refrigerator/freezer temperature. For hemp seeds produced in 2019, the most optimal storage conditions were at the refrigerator (for reduction of the total number of Enterobacteriaceae) and freezer temperature (for reduction of the total number of microorganisms). For the reduction of the total number of moulds and yeasts, optimal conditions were at room temperature. Ethanol (75%, v/v) was the most effective disinfectant among the tested chemicals regardless of the initial number of microorganisms, with log reduction of 3.2 (for the total number of Enterobacteriaceae), 2.9 log (for the total number of microorganisms), and total reduction of the total number of yeasts and moulds after 10 minutes, for the seeds harvested in 2019, which were far more contaminated than the seeds harvested in 2018. Considering the price of the disinfection method with ethanol, sodium hypochlorite may be a better solution for the reduction of the number of microbiota on the seeds.

2015 ◽  
Vol 16 (3) ◽  
pp. 620-627 ◽  
Author(s):  
V. Moresco ◽  
N. A. Damazo ◽  
C. R. M. Barardi

The present study aimed to evaluate the stability of Human Adenovirus type 2 (HAdV2) and Murine Norovirus 1 (MNV-1) in surface freshwater samples stored at different temperatures. For HAdV2 the stability decreased with increasing temperatures (−80 > −20 > 4 > 22 °C). The time required to reach one log reduction in viral titers (T90) was similar among all the times and temperatures by different cell-culture based methods and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The HAdV2 stability decreased with the time of storage temperature and methods employed, aside from samples stored at 22 and 4 °C which showed the lowest T90 values (50 days). For MNV-1, the samples stored at 22 and −20 °C showed higher log10 decay values, followed by 4 and −80 °C; while genome persistence was ranked as −80 > −20 > 4 > 22 °C. The T90 values were lower for samples stored at 22 °C (33 days), followed by 4, −20 and −80 °C with 111, 100 and 333 days, respectively. The results indicate that, under laboratory storage conditions, freshwater samples should be kept at 4 °C and at −80 °C for short- and long-term periods, respectively. This study provided useful information about thermal and temporal stability of the enteric viruses regarding sample storage conditions.


2019 ◽  
Vol 51 (2) ◽  
pp. 159-163
Author(s):  
B. Alev ◽  
S. Tunali ◽  
R. Yanardag ◽  
A. Yarat

Enzymes are made of protein, that is why they are sensitive molecules and are affected by storage conditions. A small change in enzyme activity during storage may cause a big error in analysis results. The aim of the study was to evaluate the effects of storage time and temperature on urease activity. Urease solutions were prepared at different activities (from 100 to 2000 U/mL) and stored at room temperature, in the refrigerator (4°C), and in the deep freezer (-18°C and -80°C). Activity measurements were made at regular intervals until 28 days by the modified Weatherburn method. The relative activities of 100-1000 U/mL urease solutions stored at room temperature, 4, -18 or -80°C were 75% and below after 4 days. Twenty-eight days later, for 2000 U/mL urease solutions, only at room temperature, the relative activity was reduced to 37%, while at 4, -18 or -80°C, the relative activities were above 80%. Since urease can be maintained at 4°C for 28 days without significant loss of activity, it has practical importance. Low-activity urease solutions (such as 100-1000 U/mL) should not be stored at -18 or -80°C for short or long term storage, they should be stored at 4°C only for one day. Keywords: Urease activity, storage time, storage temperature


1986 ◽  
Vol 53 (4) ◽  
pp. 615-624 ◽  
Author(s):  
Geoffrey R. Andrews

SummaryThe rates of change in light reflectance and in CIELAB tri-stimulus colour values were compared for direct and indirect ultra heat treated (UHT) and sterilized milk in glass and polyethene bottles stored under different conditions. The rate of change of milk reflectance was higher at shorter wavelengths and the milk colour changed more rapidly at 30 and 37 °C than at room temperature. Sterilized milk in polyethene bottles was bleached when stored in an illuminated cabinet. The colour of skimmed milk changed more rapidly than that of whole milk. The rate of change in reflectance of direct UHT milk above 590 nm was found to be higher than in other milks. A statistical interaction was found between the fat content and the storage temperature for the CIELAB values. The homogenization pressure used in processing UHT milk samples did not affect the rate of change of the milk colour. The main implication of these findings may be that milk colour cannot be used to assess the heat treatment of a milk when the age or storage conditions of the milk are unknown.


Beverages ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 68 ◽  
Author(s):  
Andrew Cotter ◽  
Helene Hopfer

Although from a food safety point, coffee is considered a shelf-stable product, changes in volatiles over time due to out-gassing and chemical reactions lead to perceivable differences in coffee aroma and “freshness”. Previous studies have looked at the impact of storage conditions on ground or brewed coffee. This study seeks to answer the question of how coffee consumers perceive the smell of coffee grounds of whole beans that have been stored under different conditions: freezer vs. room temperature for 9 weeks compared to a newly roasted control (stored for 1 day). Green beans from the same production lot were roasted to two different levels to also evaluate the impact of roast level on aroma changes. Using projective mapping (PM) followed by ultra-flash profiling (UFP), 48 coffee consumers evaluated, using only smell, 6 different freshly ground coffee samples presented in blind duplicates. In parallel, the profiles of 48 previously reported important coffee volatiles were measured by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) to relate chemical changes to perceivable sensory aroma changes. Overall, consumer product maps mimicked the instrumental measurements in that the lighter roast coffees showed smaller changes due to storage conditions compared to the dark roast samples. Consumers also perceived the frozen dark roast samples to be more similar to the newly roasted control than the samples stored at room temperature.


2021 ◽  
pp. 1-12
Author(s):  
Hiaki Sato ◽  
Yoshiaki Norimatsu ◽  
Satoshi Irino ◽  
Takeshi Nishikawa

<b><i>Introduction/Objective:</i></b> Liquid-based cytology (LBC) is advantageous as multiple stained specimens can be prepared and used for additional assays such as immunocytochemical and molecular-pathological investigations. Two types of preservative-fixative solutions (fixatives) are used for nongynecologic specimens used in the BD SurePath-LBC (SP-LBC) method, and their components vary. However, few studies have evaluated the differences in antigen-retaining ability between these fixatives. Therefore, we investigated and compared the antigen-retaining ability of the fixatives in immunocytochemical staining (ICC) under long-term storage conditions. <b><i>Materials and Methods:</i></b> Sediments of cultured RAJI cells (derived from Burkitt’s lymphoma) were added to each fixative (red and blue) and stored at room temperature for a specified period (1 h; 1 week; and 1, 3, and 6 months). The specimens were then prepared using the SP-LBC method and subjected to ICC. Positivity rate was calculated using the specimens fixed at room temperature for 1 h as a control. Antibodies against Ki67 expressed in the nucleus and against CD20 and leukocyte common antigen (LCA) expressed on the cell membrane were used. <b><i>Results:</i></b> For CD20 and LCA, the positivity rate increased with time in the red fixative compared with that in the control. In the blue fixative, the positivity rate was highest at 1 h and was maintained at a high level throughout the storage period. In contrast, the Ki67 positivity rate was highest at 1 h in both red and blue fixatives and markedly decreased with time. Therefore, although refrigerated (8°C) storage was used, no improvement was noted. <b><i>Conclusions:</i></b> Long-term storage is possible for cell membrane antigens at room temperature; however, it is unsuitable for intranuclear antigens. Therefore, we conclude that suitable fixative type and storage temperature differ based on antigen location. Further investigation is warranted.


1997 ◽  
Vol 33 (2) ◽  
pp. 149-155 ◽  
Author(s):  
A. E. OSMAN ◽  
F. GHASSALI

Two shrub species, Atriplex halimus L. and Salsola vermiculata L., are considered useful for rehabilitation of degraded rangelands in west Asia and north Africa. They can be established from direct seeding and are capable of self-sowing. In this study, seed storage at different temperatures and the influence of fruiting bracts on seed germination were examined for the two species during two seasons. Fruits (utricles) were stored at 20–22°C (room temperature), 0°C or −22°C. Germination tests were carried out after 33, 56, 90, 152, 272 and 397 d in storage in the first season and after 44, 76, 104, 170, 288 and 412 d in the second season. Seeds were germinated in their fruiting bracts or after bract removal. Bract removal significantly improved seed germination of both shrubs regardless of storage temperature. For S. vermiculata the increase in germination was in the range of 1.3- to 14.7-fold compared with values for the intact fruit in Season 1 and 0.5 to 3.8 in Season 2. Similarly the ranges for A. halimus were 0.5- to 4.2-fold and 0.7- to 5.3-fold in the two seasons respectively. The effect of cold storage was greater on Salsola than on Atriplex. The reduction of the storage temperature from 21°C to 0°C and −22°C increased the longevity of S. vermiculata seeds by 2.8–46.6 times in Season 1 and by 2.9–2.6 times in Season 2. There was little or no effect on the longevity of A. halimus. A leachate prepared by soaking fruiting bracts from S. vermiculata significantly depressed germination (p < 0.01), the effect being greater on Salsola seeds (20% reduction) than on Atriplex seeds (8% reduction). A leachate from A. halimus produced a slight but non-significant reduction in germination.


Author(s):  
C. Peixoto ◽  
A. Butt ◽  
C.G. Takoudis

The relationship between storage conditions and wettability of annealed micro-rough samples was investigated in this study. Micro-roughness (2.45 ± 0.43 μm) was obtained through sandblasting and acid-etching in sulfuric acid and hydrogen peroxide. Non-annealed samples (control) and samples annealed at 400 °C and 600 °C were used. In order to investigate the influence of storage conditions on the surface wettability, Ti-6Al-4V disks were 1) wrapped in Kimwipe inside a plastic bag, 2) stored in petri-dishes containing 20 mL deionized water (DI-water) at room temperature, and 3) stored in petri-dishes containing 20 mL cold DI-water (8 ± 2 °C). Surface characterization was conducted using water contact angle (WCA) measurements, white light interferometry (WLI), and fourier transform infrared (FTIR) spectroscopy. Disks immersed in DI-water maintained higher wettability when compared to Kimwipe groups over the course of 34 days regardless of the storage temperature. In addition, samples annealed at 600 °C showed superior wettability due to the rutile nature of the oxide film.


Author(s):  
B A Middleton ◽  
L M Morgan ◽  
G W Aherne ◽  
V Marks

The performance in radioimmunoassay of four antisera after storage at temperatures ranging from −40°C to room temperature, in three physical states (frozen, liquid or freeze dried) was investigated over a 3-year period. No deterioration in antiserum performance in terms of precision and accuracy of quality control serum measurement or recovery of ligand was apparent under any of the storage conditions studied. Some lowering of titre became apparent in two of the antisera over the study period. Deterioration was most marked when antiserum was stored lyophilised at room temperature. Storage of antiserum frozen confers no advantage over storage at 4°C provided precautions are taken to minimise bacterial contamination when storing antiserum in liquid form.


Author(s):  
Ana Isabel Machado ◽  
Rita Fragoso ◽  
Ana Vitória Martins Neves Barrocas Dordio ◽  
Elizabeth Duarte

This study developed a method for furosemide quantification through high performance liquid chromatographic technique. Special attention was given to solute loss and storage stability due to furosemide’s low solubility and photosensitivity, respectively. The performance of Nylon and PVDF filters was tested in a 2 mg.L-1 furosemide solution. PVDF filters showed better recovery capacity and therefore are more suitable for furosemide filtration.  Over eight days, three different storage conditions were studied to access furosemide degradation susceptibility: (i) exposure to light at room temperature, (ii) storage at room temperature without exposure to light, and (iii) storage at 4ºC without exposure to light. The study demonstrated that after 48 h under natural light exposure furosemide was completely degraded. Furosemide solution stored in the dark was stable. Storage temperature did not seem to affect furosemide concentration. The study shows that the selection of more suitable filter and storage conditions for furosemide determination is crucial to avoid underestimation errors.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mina Zareie ◽  
Azam Abbasi ◽  
Shiva Faghih

Nowadays, fortified vegetable oils with vitamin D3 are widely available in different countries. In this study, the influence of storage conditions including light, air, storage temperature, and time on vitamin D3 retention in fortified canola oil was evaluated. Moreover, a kinetic study on vitamin D3 degradation in the oil was done. To this aim, fortified canola oil was prepared at two initial concentrations of 6.87 mg·kg−1 and 13.8 mg·kg−1 and then filled in transparent and dark-brown polyethylene terephthalate bottles at two filling levels of 50% and 100%. Samples were kept in two temperatures of 4°C and room temperature (27°C). The retention of vitamin D3 in different samples showed that the vitamin content was affected by the packaging type, storage temperature, and initial concentration. Vitamin D3 in the samples with a lower concentration of the vitamin which was stored in the refrigerator showed the highest retention (91%) after 70 days of storage, and the samples with higher initial concentration packed in transparent containers which were stored at room temperature (RT) showed the greatest loss (55.6%). Results of the kinetic study also showed that vitamin D3 was affected by storage condition. The half-life of the vitamin D3 differed from 96 to 577 days depending on the storage condition.


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